The present invention solves the need for an inexpensive height adjustable pedestal which may be used in tables and chairs. The present invention typically uses at least two inexpensive telescoping spring height adjustment lifting mechanisms which may be locked at various heights. The telescoping spring height adjustment lifting mechanisms used in the present invention are typically gas springs which utilize an internal pressurized gas as the spring. In these gas springs, the pressurized gas is sealed within the cylinder section of the mechanism. The pressurized gas pushes on a piston section of the mechanism. The piston is axially aligned within the cylinder. Alternatively, telescoping spring height adjustment lifting mechanisms, which use a metal coil sealed within a cylinder as the spring and a fluid filled cartridge as the locking mechanism, may also be used. In this version the metal coil pushes on a piston which is axially aligned within the cylinder. An example of this type of spring mechanism is shown in U.S. Pat. No. 5,078,351 which is incorporated herein by this reference. In either of these versions, an actuation button on the cylinder of the telescoping spring height adjustment lifting mechanism is used to actuate or unlock the mechanism. In the actuated condition, a height adjustment may be made either by compressing the spring or by allowing a compressed spring to extend. During these height adjustments the telescopic sections of the telescoping spring mechanism move relative to each other as the spring is compressed or as a compressed spring extends. In gas springs, the actuation button is an extension of an internal gas flow control valve which allows pressurized gas to move through the valve.
The present invention uses two or more telescoping spring height adjustment lifting mechanisms to support the table top, chair seat, or other furniture component. The loads on the table top, chair seat, or other furniture component are therefore distributed over more than one telescoping spring lifting mechanism.
It has been recognized that there is difficulty in using a telescoping spring mechanism in a height adjustable pedestal due to binding or jamming problems caused within the telescoping spring mechanism. The problem arises from off center or lateral loads which may typically be placed on the table top at a lateral distance from the telescoping spring mechanism. The off center or lateral loads result in bending moment forces on the telescoping spring mechanism. The bending moments cause the telescopic sections of the telescoping spring mechanism to move out of axial alignment. Once the telescopic sections have moved out of axial alignment, the telescoping sections bind against each other. Telescoping movement of the telescopic sections is resisting by the binding.
There have been attempts at solving the binding problem inherent in the use of a telescoping spring mechanism in tables and chairs. These attempts have included the use of telescoping bracing mechanisms which are used in addition to the telescoping spring mechanism. The telescoping bracing mechanisms act to resist the bending moments which would otherwise bind or jam the telescoping spring mechanism. A height adjustable table that includes telescoping bracing mechanisms is shown in U.S. Pat. No. 4,381,714. In the description of prior art in this patent, there is discussed the problems encountered when using a telescoping spring mechanism in a height adjustable pedestal. The patent describes the binding problems which are caused by the placement of a load in an off center or lateral position relative to the telescoping spring mechanism. In the table shown in U.S. Pat. No. 4,381,714 the binding problem was addressed by the use of a pair of telescoping bracing mechanisms. The telescoping bracing mechanisms use sliding ball bearing guides. The telescoping bracing mechanism resist bending moments caused by off center or lateral loads. The resistance of bending moments on the telescoping spring mechanism minimizes any axial mis-alignment that could result in the telescopic sections of the telescoping spring mechanism. By minimizing axial mis-alignment, the bracing mechanisms ensure that the telescoping spring mechanism will not bind or jam.
The telescoping bracing mechanisms, as shown in U.S. Pat. No. 4,381,714 do not use a spring and do not contribute to the lifting forces applied to the table top, but only serve as guides. The telescoping bracing mechanisms do not support the table top in any way other than resisting the bending moments that would otherwise bind or jam the telescoping spring mechanism.
It is believed in the industry that the binding problems encountered when using a single telescoping spring mechanism would be worsened if more than one telescoping spring mechanism were used. Because of this belief, additional mechanisms other than telescoping spring mechanisms have been used to brace the telescoping spring mechanism against bending moments to minimize the binding problem. This is shown in the previously mentioned U.S. Pat. No. 4,381,714. There is no evidence in the prior art of the use of more than one telescoping spring mechanism where a load is distributed between the telescoping spring mechanisms.
The present invention allows the load of a table top, as well as any additional load placed on the table top, to be distributed to more than one telescoping spring mechanism. Similarly, the present invention allows the load of a chair seat, as well as any additional load placed on the chair seat, to be distributed to more than one telescoping spring mechanism. Height adjustments made to a table top, chair seat, or other furniture component which is supported by the pedestal of the present invention, are made by the combined lifting forces of more than one telescoping spring mechanism. Each telescoping spring mechanism contributes to the combined lifting forces applied to the table top, chair seat, or other furniture component. During the lifting of the table top, chair seat, or other furniture component, as well as during normal use of the table top, chair seat, or other furniture component when no height adjustments are made, the downward forces resulting from the table top, chair seat, or other furniture component are distributed over each telescoping spring mechanism. These features are not shown in the prior art.
Through the use of more than one telescoping spring mechanism the present invention not only distributes the forces on the table top or chair seat over more than one mechanism, as previously mentioned, but the present invention in using more than one telescoping spring mechanism also solves the binding problem. It has been determined that the use of more than one telescoping spring mechanism greatly reduces the binding problem, instead of exacerbating the problem. The additional telescoping spring mechanisms do not only function as additional lifting mechanisms which also support the table top or chair seat, but as well act to laterally stabilize the lifting of the table top or chair seat during height adjustments. The additional telescoping spring mechanisms also function as braces to ensure that off center or lateral loads on the table top or chair seat will not cause the mis-alignment of telescopic sections of the telescoping spring mechanisms resulting in binding. Loads may be placed at various locations on the table top, chair seat or other furniture component while ensuring that the height adjustment feature continues to operate properly. This use of a plurality of telescoping spring lifting mechanisms which serve as lifting supports for a table top or chair seat, as well as serving as braces for the other telescoping spring mechanisms is not shown in the prior art.
The benefits of the present invention are very pronounced in variations of the invention where the telescoping spring mechanisms are maintained within the pedestal at a significant spaced apart configuration. In these pedestal configurations, the telescoping spring mechanisms, the base sections which support the telescoping spring mechanisms, and the table top supports which are disposed above the telescoping spring mechanisms, are all placed at a spaced apart configuration which resist the bending moment forces applied by off center or lateral loads on the telescoping spring mechanisms which would cause binding. The benefits are also due to decreased bending moments as loads would necessarily be placed at a closer proximity to the lifting mechanisms. Accordingly, many more load placement locations are available on the table tops of the present invention as compared to pedestals using a single telescoping spring mechanism.
Due to the spaced apart attachment points of the height adjustable columns to the table top and to the base sections, a high level of stability is provided to the table. The stability of this configuration is considerably higher than a configuration where a single attachment point exists between a height adjustable pedestal and the table top. The high level of stability is yet another benefit provided by the present invention.
The present invention provides various actuation mechanisms which are used to unlock height adjustable tables or pedestals. The actuation mechanisms disclosed herein may be used to actuate a single locking telescoping spring mechanism. The actuation mechanisms also may be connected so that two or more telescoping spring mechanisms may each be actuated by a single mechanism.
The actuation mechanisms provide significant ergonomic benefits to height adjustable tables using locking telescoping spring mechanisms. The actuation mechanisms are designed for placement on the table at positions which are convenient for the user. The actuation mechanisms are very simple in use. Users of height adjustable chairs will readily understand the operation of the tables. The actuation mechanisms are also designed so that the shape of the elements within the mechanism which will be handled by the user are designed to accommodate the movement that the user will perform while operating the actuation mechanism. For example, if the user will be assisting the telescoping spring mechanism while the mechanisms are being actuated, the actuation mechanism is designed to allow the user to grasp ergonomic designed handles on the actuation mechanism which are in a proper position for the user to simultaneously actuate the telescoping spring mechanism and assist the lifting the table top. Similarly, if the user will be pressing downward on the table top while actuating the telescoping spring mechanism, the ergonomic designed handles are designed to allow the user to perform both functions simultaneously.